History.com: How the 1968 Sanitation Workers' Strike Expanded the Civil Rights Struggle

With the slogan, "I am a man," workers in Memphis sought financial justice in a strike that fatefully became Martin Luther King, Jr.'s final cause. On February 12, 1968, 1,300 Black sanitation workers in Memphis began a strike to demand better working conditions and higher pay. Their stand marked an early fight for financial justice for workers of color as part of the civil rights movement. The strike also drew Martin Luther King, Jr. and fatefully became the setting for his "I've Been to the Mountaintop" speech and his assassination.